Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 637 PM EDT Sat Jun 17 2023 Valid 12Z Wed Jun 21 2023 - 12Z Sun Jun 25 2023 ...Guidance Evaluation/Preferences... The 12 UTC GFS/ECMWF/CMC/UKMET and NAEFS/ECMWF ensemble mean solutions seem even better clustered over the next week, albeit with some day to day solution adjustments. Multi-model ensemble spread has decreased, bolstering forecast confidence. Stream energy phasing differences have eased from yesterday, especially early in this period/next midweek. There is also a clear guidance signal to shift the brunt of height falls/upper troughing northward over the North Slope/Arctic Ocean next week. This now supports of a stronger low/frontal system than continuity. A composite blend with a slightly greater focus on the higher resolution models still acts to maintain good WPC product continuity with detail consistent with a pattern with above normal predictability. Additional adjustments were manually applied to offshore low pressure systems to ensure sufficient depth given favorable upper support. ...Pattern Overview and Weather/Hazards Highlights... Latest guidance trends now indicate that a strong closed low/amplified trough aloft and surface focus to center over Northwest Alaska and nearby Arctic Ocean over the next few days should along with focus eject eastward into mid-later next week. Expect northwest/western Alaska through the northern Interior and Brooks Range/North Slope to the Arctic Ocean will experience unsettled conditions to include multiple periods with locally enhanced winds and precipitation. Meanwhile farther south out from the westerlies, a leading closed upper low and associated surface low/frontal system with deepened moisture will linger mainly over/south of the Aleutians early next week. The system will gradually work eastward into and then dig over the Gulf of Alaska mid-later next week. Flow around the system favors enhanced rainfall chances from the Aleutians and Alaksan Peninsula/Kodiak Island out into South-Central, but may be slow to work further eastward toward Southeast Alaska as shielded by amplified eastern Gulf of Alaska to Interior to Southeast Alaska upper ridging. Upstream, a continued and highly energetic/active storm flow off eastern Asia and the western Pacific will continue to churn up additional low pressure systems to include deepened storm tracks toward the Aleutians and southern Bering Sea as a maritime threat next week to offer potential for high winds/waves and wrapping rains. Impacts from the system are expected to work steadily eastward toward southwest Alaska and underneath with additional triple point low focus to the Alaska Peninsula/Kodiak Island and South-Central late next week/weekend. Schichtel Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html